Image bearing composite optical material

Abstract

An image bearing composite optical material is formed as a laminated flexible sheet having an image bearing photographic quality film layer variously bonded between outer and inner translucent layers of paper, fabric, or synthetic materials. The composite optical material provides two sharply distinct appearances dependent upon being viewed under backlit or ambient illumination conditions. Full-colored and precisely detailed images are produced under backlighted conditions; a plain appearance is produced otherwise. Improved embodiments include a nonbilateral structure wherein a middle image bearing film layer is bonded over its entire adjacent surface with an outer translucent layer, and is bonded at widely separated points or along thin lines with an inner translucent layer to produce an air gap there between. The air gap embodiment negates image transmission under nonbacklit viewing conditions.

What is claimed is: 
     
       1. An image bearing composite optical material structured as a laminated sheet, comprising: (a) an outer layer of translucent material and an inner layer of translucent material;   (b) a middle image bearing layer consisting of one or more photographic film transparencies, positioned between said outer and inner layers, said middle layer bonded to said outer layer along substantially all of their adjacent surface areas and said middle layer bonded to said inter layer only at their respective perimeters;   (c) whereby, said image bearing film produces a clearly visible image when viewed from a first side of said sheet while being illuminated from a second side.   
     
     
       2. The laminated composite optical material of claim 1 wherein said outer and inner layers are selected from the group consisting of paper, fabric, and synthetic materials. 
     
     
       3. The laminated composite optical material of claim 2 wherein said bonding is accomplished by the application of an optically transparent adhesive between said adjacent surfaces and along said perimeters. 
     
     
       4. The laminated composite optical material of claim 3 wherein said adhesive is cured by a process selected from the group comprising time cured, heat cured, and light cured. 
     
     
       5. The laminated composite optical material of claim 3 wherein said image bearing layer is a single sheet of film or transparency material photographically processed to include a montage of individual film strips. 
     
     
       6. An image bearing composite optical material formed as a laminated sheet, comprising: (a) an outer layer of translucent material;   (b) a middle image bearing layer comprising one or more photographic quality film transparencies having a first side positioned flatly against a flat side of said outer layer and bonded to said outer layer along substantially all of their adjacent surface areas;   (c) an inner layer of transparent material positioned flatly against a second side of said middle layer and bonded to it by a plurality of widely separated small regions of adhesive to produce an air gap between a high proportion of their adjacent surface areas;   (d) whereby said image bearing layer produces a clearly visible image when viewed from said outer layer side and backlighted from said inner layer side, and a significantly less distinct image when not backlighted.   
     
     
       7. The laminated composite optical material of claim 6 wherein said outer and inner layers are selected from the group consisting of paper, fabric, and synthetic materials. 
     
     
       8. The laminated composite optical material of claim 6 wherein said bonding is accomplished by the application of an optically transparent adhesive. 
     
     
       9. The laminated composite optical material of claim 6 wherein said adhesive is cured by a process selected from the group comprising air cured, time cured, heat cured, and light cured. 
     
     
       10. The laminated composite optical material of claim 6 wherein said image bearing layer is a single sheet of film or transparency material photographically processed. 
     
     
       11. An image bearing composite optical material made as a laminated sheet of indefinite size, comprising: (a) an outer layer of translucent material;   (b) a middle image bearing layer comprising one or more photographic quality film transparencies having a first side positioned flatly against a flat side of said outer layer and bonded to said outer layer along substantially all of their adjacent surface layers;   (c) an inner layer of transparent material positioned flatly against a second side of said middle layer and bonded to it by a plurality of widely separated small regions of adhesive to produce an air gap between a high proportion of their adjacent surface areas;   (d) said outer and inner layers selected from the group consisting of paper, fabric, and synthetic materials;   (e) said plurality of widely separated regions being adhesive areas spaced at least one inch apart and said air gap separates said adjacent middle and inner layers by less than 2 millimeters;   (f) whereby said image bearing film produces a clearly visible image when viewed from said outer layer side and backlighted from said inner layer side, and a less distinct image when not backlighted.   
     
     
       12. The laminated composite optical material of claim 11 wherein said widely separated regions are dots of adhesive less than 2 millimeters in size and are spaced at least one inch apart. 
     
     
       13. The laminated composite optical material of claim 11 wherein said widely separated regions are a plurality of parallel lines of adhesive less than 2 millimeters in width and spaced at least one inch apart. 
     
     
       14. The laminated composite optical material of claim 13 wherein said plurality of lines include a first group of parallel lines with a first orientation and a second group of intersecting parallel lines with a second orientation. 
     
     
       15. The laminated composite optical material of claim 11 wherein said widely separated regions are lines of adhesive less than 2 millimeters in width and positioned along the peripheral edges of said sheet.